Cardiac monitoring equipment can use different approaches and strategies for noise cancellation or reduction and artifact reduction. These conventional approaches include notch filtering for 50/60 Hertz electrical artifacts or low pass filtering for high frequency emission noise. These conventional approaches, however, have several shortcomings that are troublesome for medical personnel performing evaluations.
A first drawback to conventional approaches is that frequency analysis based filtering techniques can not efficiently remove common mode noise and artifact interference that share the same frequency band with cardiac signals (commonly known as overlapping signals).
A second drawback to conventional approaches is that fixed low or high frequency band pass filtering in current demising and artifact rejection methods can not effectively track and cancel dynamic noise and artifacts (especially broad band noise and semi-white noise), such as voltage/current leakage noise generated from use of bovie knife and cardiac ablators.
Another drawback to conventional approaches is that these methods are designed for linear signal processing and analysis that may not effectively reduce the non-linear and non-stationary noise and artifacts for the cardiac signals.
A further drawback to conventional approaches is that denoising methods do not have enough intrinsic data analysis and characterization of the noise and interference in the cardiac signals which greatly limit the application and efficiency of the noise removal and artifact rejection.
There is a need to provide a method and apparatus of denoising signals and performing artifact rejection related to cardiac signals from medical patients, wherein the signals and artifacts removed overlap with the cardiac signals.
There is a further need to provide a method and apparatus that can effectively track and cancel dynamic noise and artifacts such as voltage/current leakage noise generated from use of medical instruments such as bovie knife and cardiac ablators.
There is also a need to provide a method and apparatus that can evaluate and process non-linear and non-stationary noise as well as artifacts for cardiac signals. There is a further need to provide a method and apparatus that provides sufficient intrinsic data analysis and characterization of the noise and interference in the cardiac signals to overcome the conventional method limitations for efficiency of the noise removal and artifact rejection